For those who want to use Thunderbird, it will need to be reconfigured using modern authentication. If you have a previous configuration for your CGU mail in Thunderbird, it will no longer function. Please delete the previous configuration then use the settings on the page. Thunderbird lacks Exchange support so it needs to be configured for IMAP. With IMAP you can only access your email, not your calendars, contacts, or tasks.

Note: This page was sourced from here: https://uit.stanford.edu/service/office365/configure/thunderbird-oauth2

Set up a new Thunderbird account

1. Launch Thunderbird and choose to create a new Email account.
2. When asked if you would like a new email address, click Skip this and use my existing email.
3. Enter your name as you want it to appear in the From field in outgoing mail and your email address. Then, click Continue.
4. Thunderbird will attempt to automatically configure your account settings. This will fail and a message saying "Thunderbird failed to find the settings for your email account" will display. Enter the following settings:

   Incoming:

   • IMAP
   • Server hostname: outlook.office365.com
   • Port: 993
   • SSL: SSL/TLS
   • Authentication: Oauth2

   Outgoing:

   • Server hostname: outlook.office365.com
   • Port: 587
   • SSL: STARTTLS
   • Authentication: Oauth2

   Username (Incoming and Outgoing): Your CGU email address

   Note: If you do not have OAuth2 as an authentication choice you can click the Re-test button after filling in the server information.

5. Click Done. The Thunderbird main window displays.
6. You should be prompted to complete the normal web-based two-factor authentication process.